FT-IR, Raman and DFT study of 2-amino-5-fluorobenzoic acid and its biological activity with other halogen (Cl, Br) substitution

The Fourier-transform Raman and infrared spectra of 2-amino-5-fluoro benzoic acid has been recorded and analyzed. The optimized geometry of the other halogen substitution (Cl, Br) have been computed with the help of density functional theory. The detailed interpretation of vibrational spectra of 2-amino-5-fluoro benzoic acid have performed in terms of potential energy distribution analysis. Natural bond orbital analysis on 2-amino-5-fluoro benzoic acid, 2-amino-5-chloro benzoic acid and 2-amino-5-bromo benzoic acid has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. The pKa values of 2-amino-5-fluoro benzoic acid, 2-amino-5-chloro benzoic acid and 2-amino-5-bromo benzoic acid are computed using MOPAC and it is related with HOMO–LUMO energy difference obtained from Gaussian 03 software. The biological activity of 2-amino-5-fluoro benzoic acid has been predicted based on these values. The inhibition activity of 2-amino-5-bromo benzoic acid with the protein tyrosine kinase 3LQ8 is simulated by using Autodock software.

The Fourier-transform Raman and infrared spectra of 2-amino-5-fluoro benzoic acid has been recorded and analyzed. The optimized geometry of the other halogen substitution (Cl, Br) have been computed with the help of density functional theory. The detailed interpretation of vibrational spectra of 2-amino-5-fluoro benzoic acid have performed in terms of potential energy distribution analysis. Natural bond orbital analysis on 2-amino-5-fluoro benzoic acid, 2-amino-5-chloro benzoic acid and 2-amino-5-bromo benzoic acid has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule.Figure optionsDownload as PowerPoint slideHighlights
► 2-Amino-5-Flouro Benzoic Acid [AFBA] is used in the synthesis of Styrylquinazolinones which are potential anticancer agents.
► The DFT calculation for AFBA reproduces experiment vibrational wave numbers excellently.
► The comparison of NBO values of AXBA [X = Cl, Br] suggests the pharmaceutical properties of fluorinated amino benzoic acids are greater than other halogen substituted benzoic acids.
► The HOMO–LUMO energy values and pKa values are used for the theoretical comparison of bioactivity of AXBA.